Work-clamp for buttonhole-sewing machines.



No. 657,540., Patanted Sept. u, I900.

.L-T. HOGAN.

WORK CLAMP FOR BUTTONHOLESEWING MACHINES. (Applicsfloli filed Nov. 9, 1899.

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UNITED STAT S PATENT CFFICE.

JAMES T. HOGAN, OF JERSEY OITY, NEW JERSEY, ASSIGNOR TO THE NATIONAL MACHINE COMPANY, OF NEW YORK;

WORK-CLAMP VFORBUTTO-NHOLE-SEWING MACHINES.

SPECIFICATION forming part of Letters Patent No. 657,540, dated September 11, 1900.

Original application filed June 15,1897, Serial No. 540,857. Divided and this application filed November 9, 1899. Serial No, S 736,365. on model-J To all whom it may concern: 9

Be it known that I, JAMES T. HOGAN, a citizen of the United States, residing in Jersey City, in the county of Hudson and State of New Jersey, have invented a new and useful WVork-Glamp for Sewing-Machines, of which the following is a specification.

I will describe a work-clam p embodying my invention and then point out the novel features thereof in a claim.

In the accompanying drawings, which form part of my application, Figure 1 is a vertical section taken lengthwise of the work-clamp top and bottom plates. Fig. 2 is an inverted plan or bottom view of the top plate of the work-clamp. Fig. 3 is a top view of the bottom plate of the work-clamp. Fig. 4 is a view similar to Fig. 1, illustratingaslight modification in the construction of the bottom plate of the work-clamp. 1

Similar letters of reference designate corresponding parts in all of the figures.

The work-clamp M comprisesatop plate'm', having a shank portion m and an enlarged end portion m in which is formed a large rectangular opening m On the under side of the end portion m are fastened two serrated bars m each being at ornear its ends attached to or formed integral with resilient arms m", which are attached to the under side of the end portion m of the top plate of the clamp. Ashereshowlnthearmsm areformed integral with the cross-bars Screws m serve to fasten the arms m to the top plate of the clamp. The arms m of each bar a cross the other bar 001 and their resilience is such as to move the serrated bars downwardly with reference to the top plate of the clamp. Hence when the serrated bars m eetwithany considerable resistance the armsm willbe deflected upwardly,and thus will impart to. the serrated bars a movement away from each other. This movement will have the eifect. of spreading the fabric in the clamp. The large rectangular opening in thetop plate of the clamp givesthe operator an opportunity to see the serrated .bars and the fabric beneath them.

name to this specification in the two subscribing witnesses.

The bottom plate of the clamp has a shank portion m and an enlarged end portion m. In the top of the latter is a recess m which is made in the shape of an arc of a cylinder and is provided along its central line with a slot on. The serrated bars on coact with the bottom of this recess close to the sides of its slot.. The recess m instead of being made in the shape of an arc of a cylinder, may be provided with a shoulder on for coacting with the serrated bars m to make a more positive engagementof the fabric with the clamp.

The shank portion of the bottom plate is fastened to a bar 011 which bar may be attached to a. suitable feed mechanism, such as shown and described in my application, Serial No. 640,857, filed June 15, 1897, of which the present application is a division. To the bar m is hinged a lever 077, which at its free end carries the shank portion m of the top plate m. A stud 'm rises from the bar 011 through a hole in the lever m and has pivoted to its upper end a cam-lever m which serves to adjust the lever m, so that it'will depress the top plateof the Work-clam p or per- I [hit it to rise. A spring T, surrounding the stud m and hearing at itsupper end against the lever m raises the latter and the plate m when the cam-lever m is moved to release the lever m. i

What I clairmand desire to secure by Letters Patent, is

A sewing-machine work-clamp comprising a plate having an opening therein, two serrated bars crossing such opening, each of said serrated bars having at the ends resilient supporting-arms extending across the line of the other serrated bar, substantially as speci-- fied. i Y In testimony whereof I have signed my presence of JAMES? -T. HOGAN.

Witnesses: V GEO. ErORUsE, CHARLES S. JONES; v 

